Shuangxia decoction alleviates p-chlorophenylalanine induced insomnia through the modification of serotonergic and immune system.

As a Traditional Chinese Medicine (TCM), Shuangxia Decoction (SXD) has been used to treat insomnia in oriental countries for more than thousands of years and it presents remarkable clinical effects. However, its active pharmacological fraction and the mechanism of sedative-hypnotic effects have not been explored. In this paper, we investigated active pharmacological fraction and revealed the detailed mechanisms underlying the sedative-hypnotic effects of SXD. It showed that SXD water extract compared to ethanol extract possessed better sedative effects on locomotion activity in normal mice and increased sleep duration in subhypnotic dose of sodium pentobarbital-treated mice. SXD alleviated p-chlorophenylalanine (PCPA) -induced insomnia by increasing the content of 5-HT in cortex [F (4, 55) = 12.67], decreasing the content of dopamine (DA) and norepinephrine (NE). Furthermore, SXD enhanced the expression of 5-HT1A and 5-HT2A receptors in hypothalamic and reduced serum levels of IL-1,TNF-α [F (5, 36) = 15.58]. In conclusion, these results indicated that SXD produced beneficial sedative and hypnotic bioactivities mediated by regulating the serotonergic and immune system.

Determination of five neurotransmitters in the rat brain for the study of the hypnotic effects of Ziziphi Spinosae Semen aqueous extract on insomnia rat model by UPLC-MS/MS.

Ziziphi Spinosae Semen (ZSS) has been used for treatment of insomnia in China for centuries. To reveal the influence of insomnia on the levels of the neurotransmitters including serotonin (5-HT), glutamic acid (Glu), γ-aminobutyric acid (GABA), noradrenaline (NE) and dopamine (DA), and to study the role of ZSS aqueous extract in the treatment of insomnia, an UPLC-ESI- MS/MS method was developed and validated for simultaneous determination of five neurotransmitters in the rat brain. The brain samples were pretreated by one-step direct protein precipitation with acetonitrile. The analytes were detected in positive mode with multiple reaction monitoring (MRM) and the procedure was completed in less than 10 min. The method showed a good linearity (R2 > 0.9967) with the other validation parameters were within acceptance range. The results indicated that the concentration of 5-HT, GABA and DA is significantly lower (P < 0.01) in para-chlorophenylalanine (PCPA)-induced insomnia rat model group, while Glu and NE significantly higher than those in control group (P < 0.01). Treatment with ZSS aqueous extract (4 or 8 g·kg-1·d-1 for seven days) could ameliorate the symptoms of insomnia by significantly changing the levels of the neurotransmitter parameters mentioned above. The data obtained in this study demonstrate that ZSS aqueous extract could ameliorate the symptoms of insomnia by modulating the levels of monoamines and amino acid neurotransmitters in the brain.

In silico Analysis and Experimental Validation of Lignan Extracts from Kadsura longipedunculata for Potential 5-HT1AR Agonists.

OBJECTIVES: Kadsura longipedunculata (KL) has been widely used for the treatment of insomnia in traditional Chinese medicine. The aim of this study was to explore the mechanism of the sedative and hypnotic effects of KL. MATERIALS AND METHODS: The content of KL was evaluated by HPLC-TOF-MS, and a potential target was found and used to construct its 3D structure to screen for potential ligands among the compounds in KL by using bioinformatics analysis, including similarity ensemble approach (SEA) docking, homology modeling, molecular docking and ligand-based pharmacophore. The PCPA-induced insomnia rat model was then applied to confirm the potential targets related to the sedative effects of KL by performing the forced swimming test (FST), the tail suspension test (TST) and the measurement of target-related proteins using western blotting and immunofluorescence. RESULTS: Bioinformatics analysis showed that most of lignan compounds in KL were optimal ligands for the 5-HT1A receptor (5-HT1AR), and they were found to be potential targets related to sedative effects; the main lignan content of KL extracts was characterized by HPLC-TOF-MS, with 7 proposed lignans detected. Administration of KL could significantly reduce FST and TST immobility time in the PCPA-induced 5HT-depleted insomnia rat model. The expressions of proteins related to the 5-HT1AR pathway were regulated by extracts of KL in a concentration-dependent manner, indicating that extracts of KL had 5-HT1AR agonist-like effects. CONCLUSION: In silico analysis and experimental validation together demonstrated that lignan extracts from KL can target 5-HT1AR in insomniac rats, which could shed light on its use as a potential 5-HT1AR agonist drug.

Tryptophan toxicity--time and dose response in rats.

UNLABELLED: During the past decade L-tryptophan (Trp) ingestion have been associated with a multisystemic syndrome, known as eosinophilia myalgia syndrome (EMS). Even though an epidemic studies indicated that a contaminant, 1,1'-ethylidene-bis-L-tryptophan was involved in EMS, abnormalities in metabolism of Trp have been reported in other similar clinical syndromes such as carcinoid syndrome, scleroderma or eosinophilic fasciitis. The purpose of the study was to investigate the role of Trp or its metabolite, given in different dosing regimens in induction of tissue damage. METHOD: 3 months old female rats (Charles River CD-1) were fed for 3, 6, 12 weeks on a diet containing 20% protein diet derived from casein and supplemented with 1%, 2%, or 5% Trp. On the last week of feeding, half of the animals fed on a control diet and half of the animals fed on the Trp diet were injected with 2 injections of para-chlorophenyl alanine (p-CPA), a Trp hydroxylase inhibitor, 300 mg/kg i.p. followed by 3 injection of 100 mg/kg every alternate day. RESULTS: Body weight of rats fed higher levels of Trp increased slowly and injection of p-CPA induced loss in body weight. 2/6 of the animals treated with 1% Trp and 1/6 treated with 5% Trp for 3 weeks and 2/4 animals treated with 1% Trp and 1/4 treated with 5% Trp for 12 weeks died after injection of p-CPA. No mortality was detected in 1-5% Trp treated animals. Alopecia and skin changes were seen after p-CPA in 1-5% Trp treated animals. Increased amounts of connective tissue and induction of inflammatory cell proliferation were observed in lung, spleen and in gastrocnemia muscle of rats treated with higher dose of Trp for longer period. Induction of kynurenine pathway by injection of p-CPA caused more tissue damage. It is concluded that excessive Trp or elevation of its metabolites could play a role in amplifying some of pathological features of EMS. This pathological damage is further augmented by metabolites of the kynurenine pathway.

Experimental hyperphenylalaninemia in the pregnant guinea pig: possible phenylalanine teratogenesis and p-chlorophenylalanine embryotoxicity.

Maternal hyperphenylalaninemia (HPH) due to deficient phenylalanine (Phe) hydroxylation is a recognized human teratogen associated with an increased incidence of intrauterine growth retardation, microcephaly, congenital heart disease, and mental retardation. There are no previous reports of experimental HPH during organogenesis. Sustained HPH was produced in pregnant guinea pigs by adding 3.5% Phe and 1.0% parachlorophenylalanine (pCPA), an inhibitor of Phe hydroxylase, to standard guinea pig chow. Animals consumed the supplemented test diets from gestation day 1 until killed on gestation day 17. Examination of day 17 embryos revealed that embryonic mortality was associated only with maternal pCPA administration and was independent of the degree of maternal HPH. Embryonic malformation was associated with maternal HPH as well as maternal pCPA administration. Both maternal HPH and pCPA administration were associated with embryonic growth retardation. There was no association between maternal food intake or plasma tyrosine levels and embryonic abnormality or mortality. Both Phe and tyrosine were found to be concentrated in gestation day 17 yolk sac fluid when compared to maternal plasma Phe and tyrosine. The association of embryonic malformation and maternal HPH is consistent with human data. The embryotoxicity of pCPA requires further study and highlights the necessity of appropriate controls in models of experimental HPH.